Since your on this forum rather than the OSX forum, I shall refer to the Java compatibility problems as between early OS9.1/2 and later Limewire versions. The early Mac OSs run using Java 1.2.2 and 1.3.1, both of which have been significantly patched and replaced by Java 1.4.1. The developers took the design decision to continuously modify Limewire so that it remained compatible with the most recent version of Java, so you have two options. You can either download an earlier version of Limewire which should work on your machine (this used to work well for me: http://www3.limewire.com/download/2.8.6/ ), or you can download an updated version of Java at http://developer.apple.com/java/download.html

Keep us posted on how you get on.